Various systems and applications store data in non-volatile memory. In some applications, a certain body of data is defined as a data-set that should be maintained coherently en bloc, notwithstanding failures and power interruptions. Various techniques for maintaining data-set coherency are known in the art.
For example, U.S. Pat. No. 6,769,053, whose disclosure is incorporated herein by reference, describes techniques for storing a data structure for supporting persistent storage of a set of data. In one aspect, a method stores in the data structure at least an oldest version of the set of data and a first tag identifying the oldest version in a first memory area. The method includes storing, in the data structure, at least a most recently updated version of the set of data and a second tag identifying the most recently updated version in a second memory area. The method may also include deallocating the first memory area following the storing of the most recently updated version provided there are at least two versions of the set of data in the data structure.
U.S. Pat. No. 8,874,515, whose disclosure is incorporated herein by reference, describes techniques for data versioning in a non-volatile memory. An object key associated with a data object is created. An index into an object table is generated using the object key. A version number is stored in conjunction with the data object stored in the non-volatile memory. In an object linked-list, the object key and the location information of the data object in the non-volatile memory are stored. A record associated with the data object is created in an object table. The record includes an index, a reference to the object linked-list, and the version number. The index is generated based on the object key.